In a field-effect transistor (FET), an avalanche condition can occur when a high voltage is applied across a drain to a source of the FET. In the avalanche condition, impact ionization of electron-hole pairs can generate avalanche current between a drain of the FET and a base of the FET. The ruggedness of a FET characterizes the FET's capability to withstand the avalanche current when subjected to unclamped inductive switching. Ruggedness is of particular concern in applications where the FET is susceptible to repetitive avalanche cycles. Examples include automotive systems in which the FET may be subjected to numerous instances of unclamped inductive switching over its lifetime. In these applications, significant parametric shift can occur over time if the FET is not sufficiently rugged. Planar FETs are typically employed in these applications over trench FETs, as trench FETs are unable to offer comparable ruggedness.